Keen, M. H. (1967). A history of Medieval Europe. Routledge & Paul.
芝加哥风格引文Keen, Maurice Hugh. A History of Medieval Europe. London: Routledge & Paul, 1967.
MLA引文Keen, Maurice Hugh. A History of Medieval Europe. Routledge & Paul, 1967.
警告：这些引文格式不一定是100％准确.